JPH0428811A - Burner, and device and method for removing metal - Google Patents

Abstract

PURPOSE:To quickly and surely melt and remove stuck metal by setting both gas discharging holes directing diagonally downward as annular shape so that discharged combustion assist gas and fuel gas cross in the vicinity of the stuck metal surface. CONSTITUTION:A slit nozzle in a burner for melting and removing the metal stuck to refractory wall surface is constituted with a combustion assist gas- discharging hole 13 and a fuel gas-discharging hole 14 arranged at upper part thereof. Further, the combustion assist gas-discharging hole 13 and the fuel gas-discharging hole 14 are set directing directing diagonally downward as annular shape so that the discharged combustion assist gas and fuel gas cross in the vicinity of the metal surface. This burner is arranged at the tip part of a long lance, and by ascending/descending the long lance on the axis of a molten metal treating vessel, the stuck metal is melted and removed. By this method, the operational time and system can be made more flexible.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention is directed to a molten metal processing vessel, such as an RH vacuum degassing vessel, a DH vacuum degassing vessel, a converter mouth, and an inner wall of a ladle. The present invention relates to a burner used to quickly and reliably melt and remove ingots adhered to the peripheral surface of a metal, an ingot removal device using the burner, and an ingot removal method.

(Prior Art) Conventionally, ingots attached to the inner wall of a molten metal processing container such as an RH vacuum degassing container, a DH vacuum degassing container, the furnace opening of a converter, or even a ladle, etc. Special Public Service 1986-
It has been removed by a method using a long lance as proposed in Japanese Patent No. 60887. That is, this Japanese Patent Publication No. 61-60887 discloses that a long lance is moved up and down along the narrow part of a molten metal processing container, and a gas ejecting part provided at the tip of the long lance is used to blow gas around the inner wall of the container. A technique has been proposed in which the base metal adhered to a surface is melted and removed by injecting fuel gas to the base metal.

(The problem that the invention attempts to solve!! However, in the technology proposed in this Japanese Patent Publication No. 61-60887, only the fuel gas is injected into the adhered metal, so it is necessary to remove the metal.) In many cases, it is difficult to reliably achieve the purpose.This technology is a technology in which fuel gas alone is supplied to the attached metal, and the metal is heated and removed. This is because it is theoretically difficult to heat adhered and solidified metal to a high temperature and melt it using this technology, as it is not a technology that also supplies oxidizing gas.

Further, as another technique, there is a technique in which a combustion-supporting gas such as oxygen gas alone is supplied to the adhered metal without supplying fuel gas. However, with this technique, unless the temperature of the base metal is at a high temperature of about 1000° C. or higher, the exothermic reaction between oxygen and the base metal (or the exothermic reaction between the base metal and a mixture such as slag) is difficult to proceed.

In other words, the conventional metal removal method in which a long lance is used to inject a single fuel gas or a combustion-supporting gas onto the adhered metal is effective when the adhered metal is at a high temperature; If the temperature is not high, there is a problem in that the metal does not melt much, making it difficult to remove the metal.

In this way, for example, the upper inner circumference of an RH vacuum degassing container or various molten metal processing containers after being left to cool,
The temperature of the metal that adheres to the inner wall of the container without being discharged outside the container drops significantly when the operation is stopped, so with conventional technology, it is not possible to melt and remove the metal when the operation is stopped. It was almost difficult.

The present invention solves these problems and provides a base metal that can reliably and quickly melt and remove base metal adhered to the inner wall surface of a molten metal processing container even when the base metal is not in a high temperature state. It is an object of the present invention to provide a gold removal device, a burner that can be used in the metal removal device, and a metal removal method.

(Means for Solving the Problems) Thus, the gist of the present invention is to provide a burner that melts and removes a base metal attached to a refractory wall surface, comprising: A slit nozzle is constituted by a gas discharge port and a fuel gas discharge port provided above the gas discharge port, and (11) the discharged combustion-supporting gas and fuel gas intersect near the surface of the base metal. , wherein the combustion-supporting gas discharge port and the fuel gas discharge port are disposed so as to be oriented diagonally downward in an annular shape.

To explain the burner according to the present invention in more detail, it is a bare metal burner that melts and removes the bare metal attached to a refractory wall surface, and includes: (i) a combustion-supporting gas flow provided at the axial center of a long lance; a support member fixed to the lower end of the road and having a plurality of combustion-supporting gas holes; (11) a conical support located below the support member, a part of which is screwed and supported by the support member; a combustible gas radiation current-changing member; (ii) a part of which is screwed and supported by a lower end of a fuel gas flow path provided on the coaxial outer periphery of the combustion support gas flow path; and (tv) a cooling water pipe, forming a combustion-supporting gas discharge port between the separation member and the combustion-supporting gas radiation flow-changing member. , a metal removal burner characterized in that a fuel gas discharge port is formed between the separation member and the lower end of the cooling water pipe.

In addition, in the present invention, as the combustion-supporting gas, in addition to pure oxygen gas, for example, an appropriate amount of air may be mixed in and used depending on the temperature of the base metal, the adhesion status, etc.

Another aspect of the present invention is that a long lance is moved up and down at the axial center of a molten metal processing container, and gas is injected from the tip of the long lance to the base metal attached to the inner wall surface of the container. The ingot removing device melts and removes the ingot, characterized in that the burner described above is provided at the tip of the elongated lance.

Another aspect of the present invention is that a long lance is moved up and down at the axial center of the molten metal processing container, and the molten metal is attached to the inner peripheral wall surface of the molten metal processing container from the tip of the long lance. In the metal removal method in which gas is injected onto the metal to melt and remove the metal, oxygen gas is ejected from the tip of the long lance toward the oblique direction of the circumference, and at the same time, the oxygen gas is ejected from the top of the oxygen gas ejected air flow. This metal removal method is characterized in that the metal is heated and removed by ejecting fuel gas of 50% or less of the stoichiometric ratio in the combustion reaction along the oxygen gas jet stream.

In the metal removal method according to the present invention, the long lance is moved upwardly from below about the axial center in the molten metal processing container, while the oxygen gas and combustion gas are transferred to the ground. It is preferable to heat and remove the metal by injecting it onto the gold.

(Operation) Next, the present invention will be described in more detail with reference to the accompanying drawings.

Fig. 3 is a schematic explanatory diagram showing one embodiment of the metal removal device according to the present invention, Fig. 2 is a schematic longitudinal cross-sectional view showing an enlarged tip of the lance, and Fig. B in Figure 2
FIG. 4 is a schematic horizontal sectional view showing the -B cross section, and FIG. 4 is a detailed explanatory diagram showing the behavior of the combustion-supporting gas and fuel gas in the section A shown in FIG. 1.

First, a burner according to the present invention and a metal removal device incorporating this burner will be explained.

In the present invention, the upper wall 1 of the vacuum degassing container 1 shown in FIG.
A lance insertion/inlet 2 that penetrates the inside and outside is provided in the center of the tank, and a lance 3 is inserted by a lance lifting guide 4, and a lance can be inserted into the tank from the entrance/exit 2, and a person can be moved.
The structure is such that it is guided in its vertical movement.

The lance elevating drive device 5 is a device for elevating and lowering the lance 3, and includes a wire lobe 5a connected to the top of the lance 3, a pulley 5b guiding the wire lobe 5a, and the other end of the wire lobe 5a. It is comprised of a drum 5c on which is mounted, winding and unwinding, and an electric motor 1i5t1 that rotates the drum 5C.

In addition, in FIG. 1, S indicates the base metal adhering to and solidifying on the inner wall circumferential surface of the vacuum degassing container 1, and 1b indicates the refractory, respectively.

As shown in FIG. 2, the lance 3 has a combustion-supporting gas flow path 6b in its center and a fuel gas flow path 7b outside thereof.
Furthermore, double-walled cooling water candies/drainage channels 8b and 8c are formed on the outside, which are connected through the tip of the lance. A combustion-supporting gas supply pipe 6a is connected in communication with the fuel gas flow path 7b, a fuel gas supply pipe 7a is connected in communication with the inlet of the fuel gas flow path 7b, and a cooling water supply pipe is connected to the inlet of the cooling water supply path 8b. 8
A is connected in communication with the cooling water drain pipe 8d, and a cooling water drain pipe 8d is also connected in communication with the outlet of the cooling water drain channel 8c.
A, 7a, 8a, and 8d are flexible tubes that are movable within the range of vertical movement of the lance.

The burner according to the present invention is a burner that melts and removes a base metal attached to a refractory wall surface, and in FIGS. 1 and 2, (i) a combustion-supporting gas discharge port 13 and A two-stage slit nozzle with a fuel gas discharge port 14 provided above is configured, and (ii) the discharged combustion supporting gas and fuel gas intersect near the surface of the base metal S. The combustion-supporting gas discharge port 13 and the fuel gas discharge port 14 are arranged so as to be oriented obliquely downward in an annular shape. here,[
"A slit nozzle is configured" means that the combustion-supporting gas discharge port and the fuel gas discharge port are each formed in the shape of a slit, that is, annular (including disks and cones) members are overlapped with a certain gap. At the same time, gas discharge ports are formed around the entire circumference,
This means that a uniform thin film of gas can be ejected all around the circumference.

More specifically, in FIG. 2, (i) a support member 12 fixed to the lower end of the combustion-supporting gas flow path provided at the axial center of the long lance 3 and having a plurality of combustion-supporting gas holes; (ii) a conical combustion-supporting gas radiation current-changing member 11 located below the support member 12 and having a part thereof threadedly supported by the support member 12; (tti) the combustion-supporting a separation member 9 that is partially screwed and supported by the lower end of the fuel gas flow path provided on the coaxial outer periphery of the gas flow path to separate the combustion-supporting gas flow path and the fuel gas flow path; ) a cooling water pipe 15, forming a combustion supporting gas discharge port 13 between the separating member 9 and the combustion supporting gas radiation current changing member 11, and a lower end of the separating member 9 and the cooling water pipe 15. This metal removal burner is characterized in that a fuel gas discharge port 14 is formed between the base metal removal burner and the fuel gas discharge port 14.

That is, as shown in FIG. 2, the tip (lower end) of the lance 3 is separated from the lower end of the combustion-supporting gas flow path 6b and the lower end of the fuel gas flow path 7b by the separation member 9. , the separation member 9 is threadedly connected to the tube 10. A conical combustion-supporting gas radial current-changing member 11 is provided at the lowest end of the combustion-supporting gas flow path, and the combustion-supporting gas radial current-changing member 11 is connected to a support member 12.
The support member 12 is fixed to the inner periphery of the separation member 9 and has a plurality of combustion-supporting gas holes 12a.

With such a configuration, as shown in FIG. 2, the combustion-supporting gas discharge port 13 is formed by the separation member 9 and the combustion-supporting gas radiation flow transformation member 11, and the combustion-supporting gas flow path 6b
The combustion-supporting gas that has passed through the combustion-supporting gas holes 12a is injected from the entire circumference from the combustion-supporting gas discharge port 13, forming a radially uniform combustion-supporting gas flow film.

Further, the fuel gas discharge port 14 is formed by the separation member 9 and the lower end portion of the cooling water pipe 15, and is formed by the fuel gas flow path 7b.
The fuel gas that has passed through the fuel gas discharge port 14 forms a radial, uniform film of fuel and is ejected from the entire circumference.

In this way, the combustion-supporting gas flow film and the fuel gas flow film injected from the tip of the lance 3 form two coaxial layers of the combustion-supporting gas flow film G and the fuel gas flow film F, as shown in FIG. form a flow. Hereinafter, the behavior of the injected combustion-supporting gas flow film G and fuel gas flow film F will be explained with reference to FIG. 4.

The wall of the vacuum degassing container 1 is composed of an iron skin 1a and a refractory material lb, and an adhered metal S is present on the surface of the refractory material 1b.

By the burner according to the present invention described above, the combustion-supporting gas flow film G is ejected in an annular manner at an acute angle θ toward the surface of the adhered metal S, that is, obliquely downward, and the flow of the film G is ejected on the surface of the adhered metal S. While changing the direction, combustion-supporting gas branch flows G1 and G2 are formed along the surface of the deposited metal S. The oxygen gas branch G2 flowing upward in the vacuum degassing container 1 is continuously burned while gradually diffusing and mixing with the fuel gas flow, which has changed its flow direction in the same way, and the heat generated by the combustion raises the adhered metal S to a high temperature. Heat to.

In addition, the surface condition of the adhered metal S is - When fishing on a boat, there are irregularities rather than smoothness, and these irregularities cause oxygen gas separation and turbulence in the fuel gas flow, but on the other hand, this turbulence in the flow is caused by turbulence. Since it also promotes combustion, there is almost no problem from the viewpoint of removing attached metal.

In the present invention, the deposited metal S is continuously preheated by the combustion heat of fuel gas in the first stage, and then melted and removed by an oxidative exothermic reaction with oxygen in the second stage.

That is, when removing the base metal, by raising the lance 3 at a gentle speed from the lower end inside the vacuum degassing container 1, the adhered base metal S heated to a high temperature as described above is removed.
The ingots are sequentially brought into contact with the combustion-supporting gas branch G to cause an oxidative exothermic reaction, reaching a higher temperature and being melted and removed, so that the ingots can be removed more reliably.

In the present invention, the amount of fuel gas used is limited to 50% or less of the stoichiometric ratio in the combustion reaction. , and hardly reacts with the other combustion-supporting gas flow membrane G, so the deposited metal is kept at a sufficiently high temperature at a stoichiometric ratio of 50% or less with respect to the amount of oxygen gas supplied as the combustion-supporting gas flow membrane G. This is because it can be heated up to. If the amount of fuel gas exceeds 50% of the stoichiometric ratio in the combustion reaction, the amount of fuel gas will often be excessive for the combustion-supporting gas branch G2, causing incomplete combustion and reducing energy savings. It is not preferable from this point of view either. Furthermore, if the jetting angle θ is adjusted so that the supplied fuel gas is completely combusted, the amount of combustion heat becomes excessive and there is a risk of damaging the refractory 1b. Therefore, the amount of fuel gas is changed appropriately within the range of 50% or less of the stoichiometric ratio in the combustion reaction, and the amount is adjusted according to the temperature of the deposited metal at the start of metal removal and the lance movement speed during metal removal. Decide and spray.

In addition to removing the base metal from the inner wall of the RH tank/DH vacuum degassing container, for example, when melting and removing the base metal adhering to the inner wall surface of a continuous casting tandy, etc., use a flat (wide) burner to remove it. This is desirable. At that time, the combustion-supporting gas is mixed and combusted above the wall surface, and the fuel gas is mixed and combusted near the wall surface, so that heat is transferred to the base metal and the oxidation heat raising effect by the combustion-supporting gas is continuous. Since the base metal can be easily melted and removed, there is no unnecessary (excessive) heating of the refractory wall.
Trouble such as damage can be avoided.

Next, the operation of melting and removing the deposited metal S attached to the inner wall of the RH vacuum degassing container 1 during a pause in each molten steel processing time of the container 1 using the metal removal apparatus according to the present invention will be described.

In Figure 1, opening and closing to seal the lance insertion/inlet 2!
(not shown) is opened by a moder cylinder, for example, and then the electric motor 5d is rotated at a constant speed to drive the drum 5c to rewind, thereby opening the lance 3 having the burner according to the present invention at its tip. Lower it along the lifting guide 4, insert the lance of the nuclide 1, and insert it into the tank from the inlet 2.
The tip (lower end) of the lance 3 is made to reach the height where the lower end of the adhered metal S exists. Then, the electric motor 5d is changed to a low speed, the drum 5C is driven to take up the drum 5C, and the lance is gradually raised. Gases are supplied respectively, and combustion supporting gas G is supplied from the combustion supporting gas discharge port 13, and fuel gas F is supplied from the fuel gas discharge port 14.
The adhered metal S is sequentially melted and removed from the bottom to the top of the vacuum degassing container 1 while ejecting it evenly over the entire circumferential surface of the inner wall of the vacuum degassing container 1. When the tip of the lance 3 reaches almost the same height as the upper wall 1'' of the nuclide 1, the electric motor 5d is driven at low speed, the combustion-supporting gas is supplied from the combustion-supporting gas supply pipe 6a, and the combustion-supporting gas is supplied from the fuel gas supply pipe 7a. The fuel gas supply will be stopped.

At this time, if the adhered metal still remains, the electric motor 5
The lance 3 is lowered at a constant speed by the unwinding drive of the drum 5c, the tip of the lance 3 reaches the vicinity of the upper end of the adhered metal again, and the above operation is repeated again to complete the removal of the adhered metal. do.

In this way, after the removal of the base metal S is completed, the lance 3
Move the lance upward, insert the lance into the degassing tank 1, take out the part inserted into the tank from the inlet 2, and stop it at a predetermined position.
It is left on standby until the next metal removal operation.

The opening/closing lid (not shown) is closed by a mold cylinder after the lance 3 is taken out of the tank, thereby sealing the lance insertion/inlet 2.

The injected fuel gas can be ignited when the lance tip (lower end) is located outside the container near the lance insertion point 2 when the lance is inserted, and any ignition method may be used, but there are no particular restrictions. For example, a lance may be inserted into the tank and fuel gas may be injected into the deposited metal to ignite it, or a burner flame provided in the container may be used to ignite it. good.

The injection flow rate and flow rate of the combustion-supporting gas injected from the tip of the lance 3 during the above-mentioned metal removal is adjusted to a value that provides the collision flow rate and flow rate per unit area necessary for melting and removing the metal S. 27 is preferable, and the injection flow rate and flow rate of the fuel gas is varied in accordance with the oxygen gas flow rate so that the surface temperature of the deposited metal S can be heated to about 1000° C. or higher through a combustion reaction with the oxygen gas branch flow G2. It is preferable to set it as a value. Specifically, as shown in FIG.
H Vacuum degassing container has fire resistance of 1! 3 on the surface of llb
When removing the base metal S adhered to a thickness of 0c+w, the range of the base metal adhered is ~ from the bottom to the top as described above.
While moving the lance 3 upward at a speed of 100m+s/win over the entire area, turn on the combustion-supporting gas 3! 1″/+mi
n at a flow rate of 35 m/sec, fuel gas 6 N3/mt
After injecting n (17% of the stoichiometric ratio) at a flow rate of 35111/sec, these were stopped and the metal removal status was observed, and the metal was removed almost uniformly over the entire height direction, indicating that the metal was recovered. The weight of the bullion was 12 tons.

Note that the fuel gas was ignited using the heat held by the attached metal.

When compared with the conventional method (method of injecting only fuel gas), the amount of recovered metal in the same processing time is approximately 5.
This shows an improvement of 0%, which clearly demonstrates the effectiveness of the apparatus and method according to the present invention.

(Effects of the Invention) As described above, according to the present invention, instead of injecting combustion-supporting gas (oxygen gas) or fuel gas alone, as seen in conventional long lances, combustion-supporting gas and fuel gas are injected. This combustion-supporting gas is injected with a small amount of fuel gas, and it removes metal attached to the vacuum degassing container such as RH%DH, the furnace mouth of a converter, or the inner wall of a ladle, etc. The molten metal in the containers can be melted and removed quickly and reliably between the end of processing and the start of the next processing.

In particular, unlike the conventional technology, the number of adhered metals is, for example, several tens.
Even when processing is carried out while the apparatus is not operating, such as when the temperature has dropped to about 0.05 °C, the present invention has both heat raising and melting functions, so that attached metal can be easily melted and removed. Therefore, the timing of starting metal removal is not particularly limited, and the operating hours and system can be made more flexible.

The significance of the present invention having such effects is extremely significant.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram of the ingot removal device according to the present invention; Fig. 2 is a schematic vertical sectional view showing an enlarged tip of the lance:
and FIG. 3 is a schematic horizontal sectional view showing the BB cross section in FIG. 2; and FIG. 4 is a detailed explanatory diagram showing the behavior of combustion-supporting gas and fuel gas in section A shown in FIG. be. l: Vacuum degassing container la: Iron shell 1b: Refractory 1゛: Upper wall 2: Lance insertion/inlet 3: Lance 4: Lance elevating guide 5: Lance elevating drive device 5a
: Wire row 1 5b: Pulley 5c Nidram 5d: Electric motor 6a: Combustion-supporting gas supply pipe 6b: Combustion-supporting gas flow path 7a: Fuel gas supply pipe 7b: Fuel gas flow path 8a: Cooling water supply pipe
8b, 8c: Cooling water candy/drainage channel 9: Separation member
1o: Pipe 11: Combustion-supporting gas radiation current-changing member 12: Support member 12a
: Combustion-supporting gas hole 13: Combustion-supporting gas discharge port 14:
Fuel gas discharge port I5: Cooling water pipe G: Combustion-supporting gas flow film F: Fuel gas flow film S: Adhering metal

Claims (4)

[Claims] (1) A metal removal burner that melts and removes metal adhering to a fireproof wall surface, and (i) A slit nozzle is composed of a combustion-supporting gas discharge port and a fuel gas discharge port provided above the combustion-supporting gas discharge port. and (ii) the combustion-supporting gas discharge port and the fuel gas discharge port are oriented obliquely downward in an annular shape so that the discharged combustion-supporting gas and fuel gas intersect near the surface of the base metal. A bullion removal burner characterized in that it is arranged at (2) A long lance is moved up and down at the axial center of the molten metal processing container, and gas is injected from the tip of the long lance to the metal that has adhered to the inner wall surface of the container to melt and remove the metal. 2. A gold removing device, characterized in that the bullion removing burner according to claim 1 is provided at the tip of said elongated lance. (3) A long lance is moved up and down at the axial center of the molten metal processing container, and gas is injected from the tip of the long lance onto the base metal adhering to the inner peripheral wall surface of the molten metal processing container to remove the base metal. In the metal removal method of melting and removing, oxygen gas is ejected from the tip of the elongated lance in a circumferential oblique direction, and at the same time, above the oxygen gas ejected air flow and along the oxygen gas ejected air flow, 50% of stoichiometric ratio in combustion reaction
A metal removal method characterized by ejecting the following fuel gas to heat and remove the metal. (4) Heat the ingot by injecting the oxygen gas and combustion gas onto the ingot while moving the long lance upward from below about the axial center of the molten metal processing container. - The metal removal method according to claim 3, characterized in that the metal is removed.